Learning in planning means optimizing heuristic functions from plans of already solved problems and their instances. This definition includes selection of proper heuristics in a set of pattern databases [1]}, [2]}, [3]}, [4]}, a selection of a planner from a portfolio [5]}, learning planning operators from instances [6]}, [7]}, and learning for macro-operators and entanglements [8]}, [9]}. Recent years observe a renewed interest in learning heuristic functions and this is fuelled by the success of deep learning and reinforcement learning in the same area [10]}, [11]}, [12]}, [13]}.
